A conventional receiver will be described referring to FIG. 5. In FIG. 5, the conventional receiver 1 is, for example, a television tuner installed in a portable telephone. The conventional receiver 1 includes a first signal receiving unit 2 and a second signal receiving unit 3 which receive signals from a single signal source, a combining unit 4 for combining respective signals output from the first receiving unit 2 and the second receiving unit 3, and an error corrector 5 for correcting errors in a signal output from the combining unit 4.
The convention receiver 1 further includes a receiving (RCV) quality detector 6 and a controller 7. The RCV quality detector 6 determines a quality of the received signal based on a BER (bit error rate) supplied from the error corrector 5. The controller 7 switches between a single receiving mode and a diversity receiving mode. Either the first receiving unit 2 or the second receiving unit 3 receives a signal in the single receiving mode when the determination result of the RCV quality detector 6 is better than a predetermined level. Both the first receiving unit 2 and the second receiving unit 3 receive the signal in the diversity receiving mode when the determination result of the RCV quality detector 6 is not better than the predetermined level.
A prior art related to the present invention is described in Patent Document 1.
When the conventional receiver 1 passes through an area where a broadcast signal does not exist or has a sensitivity level lower than a sensitivity level for receiving the signal in the diversity receiving mode, the determination result of the RCV quality detector 6 is not better than the predetermined level. The controller 7 consequently causing the receiver 1 to operate in the diversity receiving mode which increases power consumption of the first receiving unit 2 and the second receiving unit 3. That is, the conventional receiver 1 increases overall power consumption even in the area where the receiver 1 cannot receive broadcast signals.
Patent Document 1: Japanese Patent Laid-Open Publication No. 2006-311258.